Liquid fuel pumps for internal combustion engines



, Aug. 20,1963 F. M." EVANS 3,101,079

Filed April 15/ 1962 LIQUID FUEL FOR INTERNAL COMBUSTION ENGINES 2Sheets-Sheet 1 V /6 9 0 /8 L3 9 F181 3.5 J 34 44 59 \JJ F. M. EVANS3,101,079 LIQUID FUEL PUMPS FOR INTERNAL COMBUSTION ENGINES Aug. 20,1963 Filed April 13, 1962 2 Sheets-Sheet 2 United States Patent EJ013179LEQUID FUEL PUMPS F03, INTERNAL CQMBUSTiDN ENGINES Fraser Maelrie Evans,Uxhridge, Middlesex, England, assignor to C.A.V. limited, London,England Filed Apr. 13, 1962, S er. No. 138,615 Claims priority,application Great Britain Apr. 17, 1961 7 Claims. (Cl. 123-140) Theobject of this invention is to provide in a conven ient form a liquidfuel injection pump for internal combustion engines.

A pump according to the invention comprises in combination a body part,a rotary distributor in the body part, a rotary head at one end of thedistributor, said head and distributor being adapted to be rotated bythe engine with which the pump is associated, a transverse bore in thehead, at least one plunger in the bore, and annular cam surrounding thehead for imparting radially inward movements to the plunger as the headrotates, a first series of angularly spaced passages in the distributor,said first series of passages being in communication with the bore inthe head, a second series of angulariy spaced passages in thedistributor, a discharge passage in the distributor in communicationwith the second series of passages, a plurality of angularly spaceddischarge ports in the body part with which the discharge passage isarranged to register in turn as the distributor rotates, said dischargeports being adapted for connection respectively to injection nozzlesassociated with the cylinders of the engine respectively, a cylindricalchamber one end of which is in communication with the passages of thefirst series, and the other end of which is in communication with thepassages of the second series a pair of inlet ports adapted to registerrespectively with the passages of the first and second series in turn asthe distributor rotates, means for feeding fuel to the pair of inletports, a spill passage in the Wall of the chamber, an axially movableshuttle in the chamber, means for moving the shuttle angularly about itsaxis, means for limiting axial movement of the shuttle towards said oneend of the chamber and at least one slot in the shuttle having a helicalor inclined edge whereby the angular setting of the shuttle willdetermine at what axial position of the shuttle spill port will beuncovered, and the arrangement being such that fuel fed to the secondseries of passages will be discharged to the discharge ports in turnthrough the discharge passage by the displacement of the shuttle by thefuel fed to said one end of the chamber by the inward movements of theplunger, the timing of the commencement and/ or cessation of dischargebeing determined by the covering and/or uncovering of the spill passage.

In the accompanying drawings.

FIGURE 1 is a sectional side view of an example of the invention asapplied to a pump for supplying fuel to a four cylinder compressionignition engine.

FIGURE 2 is a fragmentary sectional side view of a modification.

FIGURES 3 and 4 respectively illustrate alternative forms for theshuttle, and

FIGURE 5 is a diagrammatic sectional side view of a further modificationof the invention as applied to a pump for supplying fuel to a fourcylinder compression ignition engine.

Referring first to FIGURE 1 of the drawings, there is provided a bodypart 1 which at one end contains a feed pump 2 of the vane type. Thispump has an inlet and an outlet formed in the body part, the inlet andoutlet being interconnected by a spring loaded relief valve (not shown)which limits the maximum pressure which can be generated by the pump,the outlet pressure of the pump 3,101,079 Patented Aug. 20, 1963 "icebelow this maximum varying with the speed of the engine.

At the other end of the body part is contained an injection jump whichincludes a rotary head 4 having formed in it a transverse bore 5. Thebore extends diametrically through the head and contains a pair ofreciprocable plungers 6. As the head rotates each plunger is movedinwardly at appropriate timing by the interaction of a roller 7 at itsouter end with a surrounding annular cam 8.

The rotary parts of the feed and injection pumps are interconnected by acylindrical distributor 9, and are adatped to be driven as a unit by theengine with which the pump is associated. In the distributor 9 is formedan axial passage 11) which at one end is in communication with the bore5 in the head at a position between the pair of plungers 6 and at itsother end is in communication with four equiangularly spaced radiallyextending passages 11 (i.e. there are as many radial passages as thereare cylinders in the engine with which the pump is to be associated).Also in the distributor 9 are formed four equiangularly spaced radiallyextending passages 12 which are disposed at the same angles as thepassages 11. The radial passages 12 are in communication with one end ofan axial passage 13 which at its other end is in communication with aradially extending discharge passage 14 which is adapted to register inturn, as the distributor rotates, with each of four discharge ports 15formed in the body part 1 and adapted for connection to the fourinjectors (not shown) of the cylinders of the engine respectively, theports 15 being angularly displaced relative to the ports 17 and 18.

The feed pump 2 is adapted to deliver fuel to an inlet passage 16 formedin the body part 1, and from this inlet passage extend three inlet ports17, 18, 19. The first inlet port 17 is arranged to register in turn witheach of radial passages 11 as the distributor rotates. The second inletport 18 simultaneously is arranged to register in turn with each of theradial passages 12 as the distributor rotates, whilst the third inletport 19 is in communication with a circumferentially extending grooveZil formed in the periphery of the distributor.

In the body part 1 is formed a cylindrical chamber 21 which extendsradially relative to the distributor 9. The outer end of this chamber isclosed by an axially and angularly movable plug 22 having a radial arm23 which is adapted to be linked to a mechanical governor (not shown)whereby it may be angularly set. At the inner side of the plug 22 thereis disposed within the chamber a reciprocable shuttle 24 having a tongue25 which engages in a slot 26 in the plug in a manner to preventrelative angular movement of the plug and shuttle whilst permitting theshuttle to reciprocate independently of the plug. The inner end 29 ofthe chamber 21 is extended angularly so as to be always in communicationwith at least one of the radial passages 12, whilst opening into thechamber 21 at a position between the plug 22 and shuttle 24- is apassage 27 which at its other end 28 is extended angularly so as to bealways in communication with at least one of the radial passages 11.Moreover, opening from the chamber 21 at a position between its innerend 29 and the pump passage 27 is a spill passage 30 incorporating aspring loaded relief valve 3 1 through which it is connected to theinlet passage 16 by means of the circumferentially' extending groove 20and the inlet port 19.

Assuming the plug 22 to be fixed, then the operation of the pump as sofar described is as follows. When the inlet ports 17, 18 are in registerrespectively with the passages 11, 12 the discharge passage 14 is out ofregister with the discharge ports 1'5. As a result :fuel flowing throughthe inlet port 17 serves to move the plungers 6 ampere Lub be inregister with one of the discharge ports 15. At

this instant the plungerse will be moved inwardly by the action of thesurrounding annular cam 3. As a result fuel will be delivered throughthe passage 2'7 to the chamber 21 thereby moving the shuttle 24inwardly. During the initial inward movement of the shuttle 24 fuel fromthe inner end or" the the chamber 21 will be discharged through thespill passage 36} until the latter is covered by theshuttle 24,whereafter 'fuel will be injected to the appropriate engine cylinderthrough the discharge port until the spill passage 39 is again uncoveredby the trailing end of the shuttle 24. The inner and outer ends ofhelically shaped edges respectively whereby the covering and uncoveringof the spill passage 3b can be effected at different axial settings ofthe shuttle 24 by varying its angular setting by angular movement of theplug 22. If desired, the slot 32, can be omitted as shown in FIG- URE 3,or alternatively the slot 33 can be omitted as shown in FIGURE 4. Itwill be understood that where, as shown in FIGURE 4, a slot 32 isprovided only at the inner end of the shuttle the angular adjustment ofthe shuttle 234 will determine the commencement of injection, whilstwhere the slot 33 is provided only at the outer end of the shuttle 2-4;(as shown in FIGURE 3) the angular setting of the latter will determinethe timing of the cessation of injection. However, where both slots 32,33 are provided as shown in FIGURE 1, the angular setting of the shuttlewill determine both the instant and commencement and termination ofinjection.

The circumferential groove 2b in the distributor 9 is connected througha non-return valve 34 to one end of a cylinder 35 formed in the bodypart 1 at the outer side of the chamber 21 and extending at right anglesto the axis of the chamber. In the cylinder is a spring loaded piston 36having an inclined face 37 co-operating with a ball 38 adapted to bearupon the outer end of the plug 22, the arrangement being such that anincrease in pressure in the inlet passage 16, due to an increase inengine speed, will cause the piston 36 to move in a direction to movethe plug 22 inwardly in the chamber 21 thereby advancing the instant ofinjection, for a given angular setting of the plug 22. A clearance isprovided between the piston 36 and the cylinder 35 to admit of escape offuel from the cylinder so as to allow the piston tobe moved by itsspring when the pressure falls.

in the modification illustrated in FIGURE 2 instead of the plug 22incorporating a radial arm 23 connected to the governor, the outer endof the plug may take the form of a pinion 3h in mesh with a rack bar iiione end of which is shaped to form a piston 41 occupying a secondcylinder 42 in the body part 1 to which fuel is admitted from the inletpassage 16. A throttle actuated lever 43 acts on the opposite end of therack bar through a balancing spring and within the second cylinder is anadjustable maximum fuel, stop 45. In this construction the deliverypressure of the feed pump 2, which is a function of engine speed, iscaused to act on the rack bar in opposition to the balancing spring andthereby hydraulic governing may be obtained.

In a further modification as illustrated in FIGURE 5 of the drawings theshuttle 24 and plug 22 are located in an axial cylindrical chamber 21 inthe distributor Si and are permitted axial and angular movement relativethereto. The angular setting of the shuttle 24 and plug 22 relative tothe distributor is controlled by means of an axially movable sleeve 45surrounding a portion of the distributor and engaged by a pin 46 passingthrough heliical slots in the distributor and a straight slot in theplug 22, the axial setting of the sleeve 45 being determined by a part47 movable angular by the governor. The axial setting or" the plug 22 isdetermined as in the previous example by the position of a piston 36.

In this modification the feed pump is a separate unit driven insynchronism with the distributor and connected to the inlet passage iii.The four equi-angularly spaced radially extending passages 11 are incommunication with the end of the chamber 21 remote from the head 4 bymeans of an axial passage 43 within the distributor. Within thelongitudinal extending passage 13 is a non-return delivery valve 49.Moreover, communieating with the circumferen ially extending groove 2bis a spill passage 3d extending into the chamber 21.

I in use when the plungers 6 are moved inwardly fuel passes via one ofthe radial passages ll and the axial passage 4-3 into the chamber 21 toforce the shuttle 2 2- towards the head. Fuel is spilled to the inletpassage id via the passage 369 until the latter is closed by the shuttle24, thereafter the fuel flows via the longitudinal pass e iii, thenon-return delivery valve 49, and one of the discharge ports 15 to theappropriate engine cylinder until the passage is again opened by theshuttle 24. As the distributor rotates fuel flows from the inlet passage16, the inlet port 1'7, one of the four equi-angnlarly spaced passagesill to move the plungers 6 outwardly. At the same time fuel passes fromthe inlet passage Ed by way of the port 18 and one of the fourequi-angul-arly spaced passages 12 to the chamber 21 to move the shuttle24 into contact with the plug 22. As in the previous example, angularmovement of the shuttle 24 varies the quantity of fuel injected into theengine whilst the longitudinal setting of the plug 22 determines thetiming of the injection into the engine.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. For use with a multi-cylinder internal combustion engine providedwith a plurality of fuel injection nozzles in communication respectivelywith the cylinders of the engine, a liquid fuel injection pumpcomprising in combination a hollow body part, a cylindrical distributormounted in a complementary portion of said hollow body part, and adaptedto be rotated by the engine, a head which is rigidly united with one endof said distributor so as to be rotatable therewith, and which isprovided with a transverse bore, at least one plunger slidably mountedin said transverse bore, an annular cam surrounding said head forimparting radially inward movements to said plunger during rotation ofsaid head, a first series of angularly spaced radial passages formed insaid distributor, an axial passage which is formed in said distributor,and which establishes communication between said first series of radialpassages and the transverse bore in said head, a second series ofangularly spaced radial passages formed in said distributor, a radialdischarge passage formed in said distributor, another passage which isformed longitudinally in said distributor, and through which said secondseries of radial passages are communicatable with said radialdischargepassage, a plurality of an'gularly spaced discharge ports formed in saidhollow body p rt at positions in which said discharge passage registersin turn with said discharge ports during rotation of said distributor,said discharge ports being adapted for connection respectively to thefuel injection nozzles of the engine, a cylindrical chamber which at oneend cornmunicatcs with said first series of angularly spaced radialpassages, and at the other end communicates with said second series ofangularly spaced radial passages, a pair of fuel inlet ports in saidhollow body part at positions in which, during rotation of saiddistributor, one of said fuel inlet ports registers in turn with saidfirst series of angulariy spaced radial passages, and the other of saidfuel inlet ports registers in turn with said second series of angularlyspaced radial passages, means for feeding fuel to said pair of fuelinlet ports, spill passage in the wall of said cylindrical chamber, anaxially movable shuttle in said cylindrical chamber, means for adjustingsaid shuttle angularly about its axis, means for limiting axial movementof said shuttle towards the end of said cylindrical chamber incommunication with said first series of angularly spaced radialpassages, and means for adjusting said shuttle axially, said shuttlehaving in at least one end thereof a slot shaped so that angularadjustment of said shuttle Will determine at What axial position saidshuttle will uncover said spill passage, and the arrangement being suchthat fuel fed to said second series of angularly spaced radial passagesWill be delivered through said discharge passage to said discharge portsin turn by displacement of said shuttle in response to fuel fed byinward movements of said plunger to the first mentioned end of saidcylindrical chamber.

2. A liquid fuel injection pump according to claim 1,

wherein said means for limiting axial movement of said 6 and including aspring-loaded relief valve in said spill passage.

5. A liquid fuel injection pump according to claim 1, and including aspring-loaded delivery valve between said discharge passage and the endof said cylindrical chamber in communication with said second series ofangularly spaced radial passages.

6. A liquid fuel injection pump according to claim 2, wherein said meansresponsive to the speed of the pump for determining the axial setting ofsaid plug comprises a spring-loaded piston which is mounted in acylinder extending transversely relative to said plug, and which ismovable against its spring-loading by fuel at a pressure dependent uponthe speed of the pump, said piston having an inclined surface throughthe medium of which the axial position of said piston determines theaxial position of said plug.

7. A liquid fuel injection pump according to claim 2, wherein. saidcylindrical chamber is axially disposed within said distributor, a pinextends through a slot in said plug and engages helical slots in saiddistributor, and means are provided for moving said pin longitudinallyrelative to said distributor so as to vary the angular setting of saidplug relative to said distributor.

References Cited in the file of this patent UNITED STATES PATENTS2,406,239 Morgenroth Aug. 20; 1946 2,922,371 Bischofi Jan. 26, 19603,035,523 Kemp et al. May 22, 1962

1. FOR USE WITH A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE PROVIDEDWITH A PLURALITY OF FUEL INJECTION NOZZLES IN COMMUNICATION RESPECTIVELYWITH THE CYLINDERS OF THE ENGINE, A LIQUID FUEL INJECTION PUMPCOMPRISING IN COMBINATION A HOLLOW BODY PART, A CYLINDRICAL DISTRIBUTORMOUNTED IN A COMPLEMENTARY PORTION OF SAID HOLLOW BODY PART, AND ADAPTEDTO BE ROTATED BY THE ENGINE, A HEAD WHICH IS RIGIDLY UNITED WITH ONE ENDOF SAID DISTRIBUTOR SO AS TO BE ROTATABLE THEREWITH, AND WHICH ISPROVIDED WITH A TRANSVERSE BORE, AT LEAST ONE PLUNGER SLIDABLY MOUNTEDIN SAID TRANSVERSE BORE, AN ANNULAR CAM SURROUNDING SAID HEAD FORIMPARTING RADIALLY INWARD MOVEMENTS TO SAID PLUNGER DURING ROTATION OFSAID HEAD, A FIRST SERIES OF ANGULARLY SPACED RADIAL PASSAGES FORMED INSAID DISTRIBUTOR, AN AXIAL PASSAGE WHICH IS FORMED IN SAID DISTRIBUTOR,AND WHICH ESTABLISHES COMMUNICATION BETWEEN SAID FIRST SERIES OF RADIALPASSAGES AND THE TRANSVERSE BORE IN SAID HEAD, A SECOND SERIES OFANGULARLY SPACED RADIAL PASSAGES FORMED IN SAID DISTRIBUTOR, A RADIALDISCHARGE PASSAGE FORMED IN SAID DISTRIBUTOR, ANOTHER PASSAGE WHICH ISFORMED LONGITUDINALLY IN SAID DISTRIBUTOR, AND THROUGH WHICH SAID SECONDSERIES OF RADIAL PASSAGES ARE COMMUNICATABLE WITH SAID RADIAL DISCHARGEPASSAGE, A PLURALITY OF ANGULARLY SPACED DISCHARGE PORTS FORMED IN SAIDHOLLOW BODY PART AT POSITIONS IN WHICH SAID DISCHARGE PASSAGE REGISTERSIN TURN WITH SAID DISCHARGE PORTS DURING ROTATION OF SAID DISTRIBUTOR,SAID DISCHARGE PORTS BEING ADAPTED FOR CONNECTION RESPECTIVELY TO THEFUEL INJECTION NOZZLES OF THE ENGINE, A CYLINDRICAL CHAMBER WHICH AT ONEEND COMMUNICATES WITH SAID FIRST SERIES OF ANGULARLY SPACED RADIALPASSAGES, AND AT THE OTHER END COMMUNICATES WITH SAID SECOND SERIES OFANGULARLY SPACED RADIAL PASSAGES, A PAIR OF FUEL INLET PORTS IN SAIDHOLLOW BODY PART AT POSITIONS IN WHICH, DURING ROTATION OF SAIDDISTRIBUTOR, ONE OF SAID FUEL INLET PORTS REGISTERS IN TURN WITH SAIDFIRST SERIES OF ANGULARLY SPACED RADIAL PASSAGES, AND THE OTHER OF SAIDFUEL INLET PORTS REGISTERS IN TURN WITH SAID SECOND SERIES OF ANGULARLYSPACED RADIAL PASSAGES, MEANS FOR FEEDING FUEL TO SAID PAIR OF FUELINLET PORTS, SPILL PASSAGE IN THE WALL OF SAID CYLINDRICAL CHAMBER, ANAXIALLY MOVABLE SHUTTLE IN SAID CYLINDRICAL CHAMBER, MEANS FOR ADJUSTINGSAID SHUTTLE ANGULARLY ABOUT ITS AXIS, MEANS FOR LIMITING AXIAL MOVEMENTOF SAID SHUTTLE TOWARDS THE END OF SAID CYLINDRICAL CHAMBER INCOMMUNICATION WITH SAID FIRST SERIES OF ANGULARLY SPACED RADIALPASSAGES, AND MEANS FOR ADJUSTING SAID SHUTTLE AXIALLY, SAID SHUTTLEHAVING IN AT LEAST ONE END THEREOF A SLOT SHAPED SO THAT ANGULARADJUSTMENT OF SAID SHUTTLE WILL DETERMINE AT WHAT AXIAL POSITION SAIDSHUTTLE WILL UNCOVER SAID SPILL PASSAGE, AND THE ARRANGEMENT BEING SUCHTHAT FUEL FED TO SAID SECOND SERIES OF ANGULARLY SPACED RADIAL PASSAGESWILL BE DELIVERED THROUGH SAID DISCHARGE PASSAGE TO SAID DISCHARGE PORTSIN TURN BY DISPLACEMENT OF SAID SHUTTLE IN RESPONSE TO FUEL FED BYINWARD MOVEMENTS OF SAID PLUNGER TO THE FIRST MENTIONED END OF SAIDCYLINDRICAL CHAMBER.